People in a building know when they are hot or cold. This device simply asks them, and then adjusts the temperature accordingly.
We've all worked in offices that get uncomfortably hot in the winter, or ridiculosly frigid in the summer, as temperatures are adjusted by some unseen malevolent force with no connection to how people's bodies actually feel. But there's an obvious way to get better information about a building: Ask the people in it. Its the tenants who know the warm spots and cold spots, what systems need fixing, and what might be dangerous. By asking them for feedback, it makes sense that things would run more efficiently.